Feeding Ecology of Osteoglossum bicirrhosum (Osteoglossiformes: Osteoglossidae) in a Central Amazon Reserve

Studies determining the feeding habits of fish are essential for understanding the relationships between fauna components and other aquatic organisms. This study aimed to evaluate the feeding habits of the Arowana Osteoglossum bicirrhosum in the Piranha Sustainable Development Reserve, located in the middle Solimões River, Amazonas state. The research covered different phases of the flood pulse (recession, flooding, flood peak, and dry phase) from September 2015 to May 2016. One hundred stomach samples were collected, with an average standard weight and length of 684.81 ± 257.73g and 44.92 ± 5.91cm, respectively, showing a high Pearson correlation coefficient (p= 0.9373905). Stomach content analysis revealed that 76% of the samples contained food, with 72% consisting of arthropods, 13% plant remains, 10% fish, 3% reptiles, and 2% mammals. The alternation of periods influenced the bioavailability of food in the aquatic environment, with arthropods, mainly insects, being identified as the primary food source for the Arowana. This indicates a generalist and opportunistic feeding behavior with a diet tending towards insectivory.